rosco28

Hi Guys,

So the other day I give a lift to a guy, a mechanic (not Porsches). We're only going a block or two so we never go above 30mph. After only a minute he starts laughing and tells me that I need to replace my rear differential. I ask him why and he says that the whine I'm hearing in the rear shows that my whole rear axle is screwed. I always thought that the whine in low gears at low revs was normal, just part of the air cooled engine sound.

Anyways, when I get home I watch a lot of 911 videos on YouTube, and low and behold all the cars sound like mine do.

So my question is: Is there anything to what this mechanic was telling me?? Do non Porsche guys often mistake the regular engine whine for a rear dist problem?

masterdave

I would say he didn't know what he was talking about. If you are really worried get a Porsche mechanic out to check it out. The other main thing you must remember is that Porsches do not actually have differentials they have transaxles, which are differentials and transmitions in one. So all the mechanics for both the trans and dif are in the same case. This causes them to sound very different than a car that has a dedicated diff in the back. The air cooling fan also creates a whine that no other car really has.

If there was an issue with the diff part of your trans then you would know. The car would not be able to turn quite right if it locked up, and if it was not driving one of the wheels you would have some interesting steering problems where the car would always be pushed one way.

Regards
Dave

KNS

Porsche trannies are known for being on the noisier side, plus, they're only a few feet behind your head. I would have laughed right back at him. If you're concerned have a Porsche tech listen to it.

Reiver

and he ain't much of a mechanic either...lots of conventional trannies whine and are just fine. If you get the preload a hair off either way they will whine for thousands and thousands of miles. I've a 68 Mustang 9" with 3.73 gears in my 'avatar' pic that I just rebuilt and it sings to me at diff rpm. I do burn outs/wheelspins all of the time, strong as an Ox....my tranny will go before that whiny rear end will.
He was busting your chops for driving that furrin fancy car.

wildcat077

When i purchased my 89 three years ago it had the stock exaust system and i was disappointed because i found that the gear whine was louder than the engine ... lol

I think the whine is part of the character of our cars

Cheers !
Phil

rosco28

I have a Bursch exhaust, and it makes great sound, but the whine is still noticeable. It doesn't bother me any, but I did get nervous when he started talking about dropping my engine, and rebuilding the whole tranny/diff box...

I think I'm all good, but I'm going to bring her by my Porsche tech to have a listen.

Thanks guys!

Reiver

Porsches are just noisy altogether...like a racing machine is noisy...like it is supposed to be. If I want quiet I'll drive the Cadillac